Fuel for thought: Four-cylinder v hybrid v LPG

There was a time when buying a big car was simple: ''Will that be a six or V8, sir?''

How times have changed. More competitors have joined the battle and fuel prices have gone through the roof.

The impact has been huge; the Holden Commodore has been deposed from the top of the sales tree by an imported small car, the once mighty Ford Falcon is struggling to stay alive and Toyota's locally made Camry and Aurion are also suffering.

But the responses to the challenge are coming thick and fast.

Ford has provided a double-barrelled solution, rolling out its first four-cylinder Falcon and a new dedicated LPG six-cylinder.

Holden launched a dedicated LPG Commodore earlier this year, while the second generation of the petrol-electric Camry Hybrid is also on sale.

All solutions have their advantages. LPG is not as efficient as petrol, but is (currently) about half the price and emits less carbon dioxide. Ford's turbocharged four-cylinder promises six-cylinder power and four-cylinder fuel economy, while the Camry Hybrid combines a 2.5-litre four-cylinder petrol engine with an electric motor for claimed small-car fuel consumption.

Drive iPad cover

But which is best? We devised a three-day drive program to find out. Day one was 220 kilometres of city and suburban running, days two and three an 880-kilometre loop into country Victoria.

The brief was to treat them as buyers would; drive them normally and fill the EcoBoost and Hybrid with the cheapest regular unleaded.

Ford Falcon XT EcoBoost

The Falcon's turbocharged four delivers a surprisingly satisfying drive, but this test is about fuel savings, and on that score the engine doesn't make a compelling case.

It was by far the most expensive of our test vehicles to fuel and emitted the most CO2. While the EcoBoost averaged a pretty impressive 9.6 litres per 100 kilometres, it couldn't overcome the price advantage of LPG or the efficiency of hybrid technology.

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Based on our returns, the XT EcoLPi should be more than $500 cheaper to fuel over 15,000 kilometres, meaning you've already negated the EcoBoost's retail price advantage of $2500 (if you are a private buyer who gets the $2000 government rebate for LPG).

If you want to get the maximum 179kW of power out of the Falcon you'll also need to spend at least 10¢ a litre more on fuel to fill it with premium unleaded. Compared with the Camry Hybrid, it costs about $250 more and pumps about 10.5 kilograms more CO2 into the atmosphere.

Where the EcoBoost starts to make more sense is when it is examined against orthodox petrol-fed six-cylinder competition. While they were not the focus of this comparison test, a 4.0-litre Falcon XT and 3.0-litre Holden Commodore Omega were also brought along.

The Omega averaged 9.9L/100km and swallowed 14.7¢ worth of ULP each kilometre. The XT averaged 10.0/100km and averaged 15.4¢ each kilometre. So over 15,000 kilometres the six-cylinder Falcon, which is priced exactly the same as the four-cylinder, is going to be $270 more expensive to fuel; the Omega, $165.

However, the Holden's recommended retail price is nearly $3000 more than the EcoBoost's.

Admittedly, no one pays recommended retail for Falcons and Commodores so basing these calculations on official RRPs is fraught with danger.

Fair enough, but what we have established here is at least a baseline, and that is that the EcoBoost
Falcon is not a fuel-economy saviour. It is an improvement, however. The engine will surprise you with the depth and breadth of its responses. Teaming neatly with a six-speed auto it never feels breathless or under-done, nor does it get noisy as revs rise. But the EcoLPi has more pulling power and a meatier response across the low- to mid-throttle range. Our acceleration figures showed only a 0.3-second gap to 100km/h. The Camry was left behind, the Commodore embarrassed.

The EcoBoost is 100 kilograms lighter than the EcoLPi and feels it. Steering is almost too light and it changes direction better than anything else here. However, its ride on revised, lowered suspension and low-rolling resistance tyres running at higher pressure, is not as smooth or quiet as the LPG Falcon.

The EcoBoost has one major advantage over the EcoLPi and that is in the boot.

The LPG car's bigger tank means boot capacity drops from 535 litres to 464 litres, while the space for a spare tyre disappears. Otherwise the Falcons were identical, in look, feel and equipment.

Ford Falcon XT EcoBoost vital statistics

Price: $37,235

Engine: 2.0-litre 4cyl turbo-petrol

Power: 179kW at 5500rpm*

Torque: 353Nm at 2000rpm*

Transmission: 6-spd auto

Fuel type: Petrol

Weight: 1648kg

Ford Falcon XT EcoLPi

The EcoLPi's new LPG system is a massive improvement in terms of refinement, performance and economy.

On the latter score, Ford claims a 27 per cent improvement to 12.3L/100km, a figure we actually improved on by 0.1L/100km. It's an excellent figure, tempered by the caveat that refuelling fully proved to be a challenge on a couple of occasions, the system insisting on clicking off even though the gauge showed the tank to be three-quarters full.

However, it balanced out over the course of the test and there's no doubting the EcoLPi's improved efficiency or its advantage over Holden's new system in the Commodore. Indeed, based purely on fuel-cost-per-kilometre figures, the Falcon EcoLPi is the most affordable car here to refuel. It pips the Hybrid Camry, has an advantage over the Holden and streets its in-house rival.

That advantage purely comes down to the lower cost of LPG. If your green consciousness is stirring, then the Camry wins based on CO2 emissions.

The EcoLPi's power and torque are both higher than its donor petrol engine, making it an ideal tow vehicle and a good option for people who want to save money but must have a six-cylinder.

Both Falcons share the car's traditional strengths and weaknesses. The suspension is well tuned and the interior roomy, but cabin materials are a bit workman-like and you sit too high in the driver's seat.

Ford Falcon XT EcoLPi vital statistics

Price: $39,735

Engine: 4.0-litre 6cyl LPG

Power: 198kW at 5000rpm

Torque: 409Nm at 3250rpm

Transmission: 6-spd auto

Fuel type: LPG

Weight: 1757kg

Holden Commodore LPG SV6

We were unable to secure a base Commodore Omega LPG for this test, so the slightly thirstier SV6 carries the banner for Holden.

The Commodore brought up the tail in this field, unable to match the fuel economy of the EcoLPi, the fuel cost per kilometre of the Camry or the performance of any of its rivals.

Forget this is an SV6 and substitute Omega pricing and even with the rebate claimed and the price dropped to $40,490, this is not an enticing proposition. It would take years to recoup its fuelling cost advantage over the EcoBoost.

Indeed, the Commodore Omega petrol is the car it threatens most clearly, rather than the four-cylinder small cars against which Holden is campaigning.

Holden claims its new LPG system is more economical than Ford's system. That might be true when quoting official figures (the Omega claim is 11.8L/100km while the SV6 is 12.3L/100km, equal to the XT EcoLPi and 0.1L ahead of the XR6), but it is not borne out by our experiences.

In every segment of our test loop, be it urban stop-start, cruise-controlled freeway stretches, rolling country highways or mountain switchbacks, the Ford was more economical. Again, we have to stress that LPG refuelling can be inconsistent but over time an unarguable trend emerges.

The Commodore also lagged in performance, completing the sprint to 100km/h two seconds slower than the EcoLPi.

Holden's 3.6-litre drops both power and torque running on LPG, going from 210kW to 180kW and 350Nm to 320Nm. At the same time, kerb weight climbs 56 kilograms. On test, our particular example of the breed felt slow and flat and the six-speed auto was forced to change down regularly to keep the Commodore moving up the same steep hills that barely required a slurring shift from the Falcon's. The downshifts were accompanied by a raucous shriek.

The SV6 does ride well, and its steering and grip are more confidence-inspiring than the Falcon's. Inside, the SV6 LPG is familiar territory, which is both good and bad. It's roomy and comfortable, but the presentation is gloomy and thick windscreen pillars obstruct the driver's forward view.

Boot space is compromised by the bigger tyre, while a spare tyre is also optional.

Holden Commodore SV6 LPG vital statistics

Price: $46,290

Engine: 3.6-litre V6 LPG

Power: 180kW at 6000rpm

Torque: 320Nm at 2000rpm

Transmission: 6-spd auto

Fuel type: LPG

Weight: 1766kg

Toyota Camry Hybrid H

The Camry consistently impressed us with its fuel economy. Here was a big five-seat sedan that provided acceptable performance yet was capable of rolling much further than its rivals on a tank of fuel.

Its miserly on-test average was 6.6L/100km, exactly three litres better than the next-best petrol-fuelled vehicle. That was achieved without opting for Eco Mode, which dulls the throttle and reduces airconditioning effectiveness.

Yet such is the fuel-price differential between petrol and LPG, the EcoLPi Falcon managed to undercut the Camry's fuel-cost-per-kilometre average, while the Commodore SV6 owner will pay only a little more.

But the Camry emits significantly less CO2 and you don't have to refuel as often as an LPG car. And at $34,990 you have paid significantly less (based on RRP).

You're also getting more gear for your money than your rivals: a reversing camera, driver's knee airbag, smart-key entry and start and a full-size spare tyre.

And the engine gets better the tougher conditions get. While the fuel consumption of orthodox cars climbs in stop-start traffic, the Hybrid's ability to shut its engine off, reclaim energy usually lost in the braking system, and use electric power alone boosts economy.

Time and again testers stepped from the Camry Hybrid impressed by its ability to respond to the throttle when needed, although the continuously variable transmission meant the engine tended to become a bit loud when pushed.

The roomy cabin has also improved in terms of presentation and quality, although the drive experience is forgettable. The ride should be more refined, grip levels are low and the brake pedal lacks progression or feel because of its regenerative function. Steering is improved but still lacking feel.

The biggest drawback is the boot size - or lack of it. The battery pack sits between the rear axles, limiting capacity to 421 litres.

Toyota Hybrid Camry H vital statistics

Price: $34,990

Engine: 2.5-litre 4cyl petrol and electric motor

Power: 151kW

Torque: 270Nm

Transmission: CVT auto

Fuel type: Petrol

Weight: 1610kg

Verdict

The Commodore and the Falcon EcoBoost get knocked out of the contest first.

The four-cylinder Falcon is a fine engineering effort but if we are judging this comparison test first and foremost on economy and fuel costs, then it clearly loses out.

The Commodore gets knocked because in a two-horse dedicated LPG race it is clearly the inferior competitor. The EcoLPi Falcon does a better job of saving you money and delivers a more satisfying drive.

Which leaves the LPG Falcon and the Camry Hybrid.

Personally, I would take the Falcon because it is a pleasure to drive and powered by a fuel that reduces our dependency on imported oil.

Yet the economy and pricing of the Camry are impossible to ignore. It is a car that lacks personality but is brainy, frugal and affordable, and deserves the top ranking in this test.